Fermi Gamma-ray Space Telescope

The second Fermi LAT GRB catalog: the features of 180 GRBs at high energy

Giacomo Vianello
(M. Axelsson, E. Bissaldi, N. Omodei, the Fermi/LAT GRB group)


The high-energy emission from Gamma-Ray Bursts (GRBs) is a formidable probe for extreme physics, calling for highly relativistic sources with very large Lorentz factors. Despite the advancements prompted by observations from the Fermi Large Area Telescope (LAT) and Gamma-Ray Burst Monitor (GBM), as well as other observatories, many questions remain open, especially on radiative processes and mechanisms. We present here the most extensive search for GRBs at high energies performed so far, featuring a detection efficiency more than 50% better than previous works, and returning 180 detections during 10 years of LAT observations. The large sample size, a great improvement from the 35 detections presented in the first Fermi/LAT GRB catalog, enables us to assess the characteristics of the GRB population at high energy with unprecedented sensitivity. We will review the results of the 10 years Fermi/LAT GRB catalog, as well as their interpretation.